Teratozoospermia index (TZI)

Teratozoospermia is a cause of male infertility due to defects in the shape of sperm.

The sperm produced has an elevated percentage of abnormal sperms. Common defects include sperms with a too big or too small head, round head (instead of oval head), double head, two tails, pin-head sperm, coiled tailpiece, bent tail, absence of midpiece, with an abnormal middle piece, amorphous, etc.

The teratozoospermia index (TZI) indicates if the sperms have defects in one only part or in multiple parts.